1. Field of the Invention
The present invention relates to an explosive, such as a multimodal explosive, in particular, for blast charges.
In the case of explosives, in particular for blast charges, aluminum powder has been used to date as a powder additive for increasing the power (i.e. increasing the pressure effect). The explosive used is, for example, RDX (=hexogen) or HMX (=octogen). The theoretically achievable increase in the detonation pressure owing to liberation of heat in the reaction with the large proportions of liberated carbon atoms of, for example, RDX or HMX is observable only in very rare cases with the use of an aluminum powder as a powder additive. With the use of non-oxidized aluminum powder, for example, an increase of about 12% in the fragment velocity can be observed. However, this increase in the fragment velocity is lost within a few weeks since pure aluminum powder rapidly builds up a multiplicity of aluminum oxide layers on the powder surface. Several thousand layers of aluminum oxide can form on the aluminum powder surface. This oxide layer has a high melting point and is very resistant to wear, so that a post-reaction can take place only in the millisecond range, and only then does improved blast behavior occur above and below water. However, investigations to date have shown that overall only a relatively small proportion of the aluminum powder reacts. This small proportion of aluminum powder which reacts is of the order of magnitude of not more than 20%.
2. Discussion of the Prior Art
German Patent Publication DE 102 04 895 A1 discloses nanostructured porous reactive substances which consist of reactive bodies whose cavities are in the size range from 1 to 1000 nm, which are provided with oxidizing agents. The reactive substances consist of reactive particles which are independent of one another and are enveloped by a protective layer. A process for the production of such reactive substances is also described there, nm size fuel particles which have interstices measuring from 1 to 1000 nm first being provided with a protective layer by heating at from 20 to 1000° C. in air or by chemical or electrochemical processes or by vapor deposition processes and the interstices then being provided with an oxidizing agent. The fuel particles provided with the protective layer and the oxidizing agent can be pressed to give a reactive body. The fuel particles may consist of silicon, boron, titanium or zirconium.